1. Field of the Invention
This invention relates to a self contained electronic braking system for mounting on a towed vehicle and then being attached to the braking circuitry of the towing vehicle to provide for automatic energizing of the braking system of the towed vehicle when the brakes of the towing vehicle are applied.
2. Prior Art Statement
Current brake control for vehicles being towed comprises a hand operated or electronic brake controller mounted in the towing vehicle near the driver. Braking of the towed vehicle requires that the driver attend to the brake lever or controller with one hand while attempting to steer with the other hand and thus safety hazards include potential loss of control of both vehicles. Most current trailer braking systems also do not provide for braking control on the towed vehicle when the towed vehicle becomes separated from the towing vehicle or when the towed vehicle is parked separate from the towing vehicle.
Pokrinchak, et al., in U.S. Pat. No. 3,738,710 issued on Jun. 12, 1973 provides an elementary timing circuit in a towed braking system to differentiate between a momentary closure and a steady closure of a towed vehicle braking switch and thus electric trailer braking is dependent upon the duration of the closure of the stoplight switch of the towing vehicle.
It is known to provide for a truck-trailer hydraulic brake system comprising a trailer brake system including an electric motor actuated by an electrical circuit through a control means associated with the brake pedal onboard the tractor or a safety switch connected between the tractor and the trailer. No means for sensing motion is provided. For instance, see the U.S. Pat. No. 3,951,464 to Donahue, et al., issued on Apr. 20, 1976.
It is known to provide breakaway protection for electrically controlled trailer brakes by placing an additional battery on the trailer connected in parallel with the battery on the towing vehicle through a breakaway switch in which primary braking control is rheostatically controlled by the driver. For instance, see the U.S. Pat. Nos. 4,052,695 and 4,066,966 issued on Oct. 4, 1977 to Philip E. Myers and on Jan. 3, 1978 to Donald L. Davis, respectively.
It is known to provide an electrical surge braking system for a trailer wherein the electrical brakes of the trailer are energized when the trailer surges forwardly relative to the towing vehicle as the effective resistance of a resistor associated with one hitch member decreases as a wiper associated with another hitch member moves along the resistor. For instance, see the U.S. Pat. No. 4,222,614 issued on Sep. 16, 1980 to John A. Spechko. Similar devices are provided for hydraulic trailer braking systems.
Also, it is known to provide a braking system for a towed vehicle manually actuated by the driver of the towing vehicle and wherein the towed vehicle has an onboard battery to provide for braking of the towed vehicle in case of separation from the towing vehicle wherein braking is actuated by a separable connector between the towed vehicle and the towing vehicle when the vehicles become separated. For instance, see the U.S. Pat. No. 3,907,071 issued on Sep. 23, 1975 to Wm. H. S. Wells.
It is also known to provide a towing vehicle mounted brake controller wherein braking of a towed vehicle is manually actuated by the driver, initiated by a signal from the towing vehicle brake system and wherein the amount of towed vehicle braking is controlled by a pendulum type grade and motion detection device on the towing vehicle. For instance, see the U.S. Pat. No. 3,909,075 issued on Sep. 30, 1975 to Pittet, Jr, et al.
Robert C. Snyder in U.S. Pat. No. 4,196,936 issued on Apr. 8, 1980 provides for electric or hydraulic trailer braking from a series of components comprising a brake controller mounted in the tractor through a separate wiring harness wherein power is supplied to a variable frequency oscillator when the brake pedal is depressed. The series of components uses a hall effect sensor for sensing of the deceleration or lateral movement of the towing vehicle and for applying the brakes dependent upon the magnitude of the motion.
Frait, et al., in U.S. Pat. No. 4,721,344 issued on Jan. 26, 1988 and U.S. Pat. No. 4,726,627 issued on Feb. 23, 1988, respectively, provide for electric trailer braking from a brake controller mounted near the driver of a towing vehicle through a separate wiring harness wherein power is supplied to the pulse width modulator of the controller only when the brake pedal is depressed or when a manually controlled lever is moved to the on position. The controller uses a pendulum for sensing of the deceleration of the towing vehicle and generates a signal representing the magnitude of the deceleration.
Additionally, it is known to provide a stability control system for a vehicle to prevent swerving and swaying comprising means for sensing lateral acceleration forces acting upon the vehicle and energizing a brake in response to signals wherein the means for sensing lateral acceleration is a pair of inclined mercury switch assemblies, hall effect or pendulum sensors. For instance, see the U.S. Pat. No. 3,861,489 issued on Jan. 21, 1975 or the U.S. Pat. No. 3,908,782 issued on Sep. 30, 1975 both to Lang, et al.
Finally, it is further known to provide a method of controlling brakes on a trailer by sensing the rate of deceleration and inclination of the towing vehicle, generating variable deceleration and variable inclination signals, sending a brake amperage output signal to the brakes of the trailer and continuously proportioning the brake amperage output in accordance with both the deceleration and inclination signals. For instance, see the U.S. Pat. No. 6,012,780 issued on Jan. 11, 2000, to Mark E. Duvernay.
The above cited braking systems, though usable in their respective environments, do not have means of transferring all control of an electronic braking system from the towing vehicle to the towed vehicle. The prior art trailer braking systems do not describe a self contained electronic braking control device mounted upon the trailer wherein the braking control device comprising a means for sensing deceleration of the trailer and means for actuating the braking system of the trailer either independent of a signal from the towing vehicle or using the braking light circuit of the towing vehicle for actuation of the brakes on the towed vehicle. Therefore, there is a great need for an electric or hydraulic trailer braking system for use with a trailer having at least one pair of wheels fitted with electrically or hydraulically actuated brakes wherein the trailer braking system is a self contained electronic braking control device mounted upon the trailer, the braking control device comprising a means for sensing deceleration of the trailer and means for actuating the brakes of the braking system of the trailer, the self contained electronic braking control device having electric circuitry connecting the braking circuitry of the towing vehicle to the braking system of the towed vehicle wherein the brakes of the braking system of the towed vehicle are automatically energized to an initial engagement state upon sensing a braking signal from the towing vehicle.
Heavy towed vehicles, particularly two and three axle vehicle trailers are required to have electric brakes operable from the towing vehicle. Such brakes usually require some hand operation by the driver of the towing vehicle presenting hazards to the driver and the other vehicles on the road. Other towed vehicles are equipped with a hydraulic braking system operated by a surge connection at the towed/towing vehicle hitch location or with an electric solenoid operating a hydraulic cylinder with an electric, pneumatic or hydraulic signal from a towing vehicle.
Therefore, it is an object of this invention to provide an electronic trailer braking system for a trailer having at least one pair of wheels fitted with electrically actuated brakes wherein the trailer braking system is a self contained electronic braking control device mounted upon the trailer, the braking control device comprising a means for sensing deceleration of the trailer and means for actuating the electrically actuated brakes of the trailer independent of a signal from the towing vehicle.
It is still another object of this invention to provide an automated electronic braking system comprising an energy source, a charging circuit, a grade and motion sensing device, a timer, a relay, a circuit breaker, a breakaway safety switch, a seven wire male plug for connecting to a cooperating female connector on a towing vehicle and a female socket plug for connecting to a seven wire male plug of a towed vehicle.
It is yet another object of this invention to provide an automated electronic braking system which may be mounted either within the towing vehicle wherein a complete brake wiring harness from a location near the driver to the braking system on the towed vehicle is installed and used to connect and actuate the electric brakes of the towed vehicle or wherein the automated electronic braking system is mounted on the towed vehicle and uses the braking light circuit of the towing vehicle for actuation of the electric brakes of the towed vehicle. When mounted on the towed vehicle, electric circuitry connects the braking circuitry of the towing vehicle to the braking system of the towed vehicle such that when towing vehicle brakes are applied, the braking system of the towed vehicle is automatically energized and the electronic brake control device containing the grade and motion device senses incline, lateral motion and/or braking and hence supplies power to the braking system of the towed vehicle dependent upon the slope of the grade, the severity of the motion or both. When made a part of the towing vehicle, a breakaway switch is in parallel connection with the electrical connection between the towing vehicle and the towed vehicle and separated from the electronic brake control device by the wiring harness. Generally, the energy source for the onboard towed vehicle mounted braking system is integral therewith but may be a separate battery, an array of solar cells, the towing vehicle energy source, a direct current or an alternating current source, a capacitor or an energy source resident in the towed vehicle or in the load carried by the towed vehicle. Similarly, the energy source for the braking system having the controller mounted within the towing vehicle is generally carried by the towing vehicle but may be one of the alternate forms recited above. The automated electronic braking system may also employ an internal charger, an external charger or both when an internal energy source is used and may also employ a seven wire to four wire adaptor for use with towing vehicles having a four wire plug.
It is another object of this invention to provide a self contained electronic brake control device comprising an upright enclosure having a separable cover, the enclosure containing an energy source, a brake controller, at least one relay and means for connecting the electronic brake control device from a towing vehicle to a towed vehicle.
One object of this invention is to provide a retrofit for an existing towed vehicle with a self electronic brake control device mounted upon the towed vehicle wherein a 4 wire female connector for connecting the electronic brake control device to a 4 wire male plug from the towing vehicle and a 4 wire male plug for connecting the electronic brake control device to a 4 wire female connector of the towed vehicle these pigtails used to connect the control device to the electrical system of the towed and towing vehicle.
Still another object of this invention is to provide a retrofit for an existing towed vehicle with a self electronic brake control device wherein a 4 wire female connector for connecting the electronic brake control device to a 4 wire male plug from the towing vehicle and a 7 wire male plug for connecting the electronic brake control device to a 7 wire female connector of the towed vehicle these pigtails used to connect the control device to the electrical system of the towed and towing vehicle.
Yet another object of this invention is to provide a retrofit for an existing towed vehicle with a self electronic brake control device wherein the means for connecting comprises a 7 wire female connector for connecting the electronic brake control device to a 7 wire male plug from the towing vehicle and a 7 wire male plug for connecting the electronic brake control device to a 7 wire female connector of the towed vehicle these pigtails used to connect the control device to the electrical system of the towed and towing vehicle.
One important object of this invention is to provide a retrofit for an existing towed vehicle with a self electronic brake control device wherein a means for connecting comprises splice connectors and connecting wires for connecting the electronic brake control device directly to a wiring loom resident within the towed vehicle.
It is also an object of this invention to provide an electronic trailer braking system for a towed vehicle having at least one pair of wheels fitted with hydraulically actuated brakes wherein the towed vehicle braking system is a self contained electric/hydraulic braking control device mounted upon the towed vehicle, the braking control device comprising a means for sensing deceleration of the trailer and means for actuating the hydraulically actuated brakes of the trailer either from a signal from the towing vehicle braking circuit or independently of a signal from the towing vehicle.
One important object of this invention is to provide a retrofit for an existing towed vehicle with a self electronic brake control device wherein a means for connecting comprises splice connectors and connecting wires for connecting the electronic brake control device directly to a wiring loom resident within the towed vehicle, and at least one hydraulic line for connecting a hydraulic pump of the self contained control device to the hydraulic brakes of the towed vehicle.
A significant object of this invention is to provide a method of controlling the braking of a towed vehicle using a braking control device onboard the towed vehicle, the braking control device comprising an energy source, a means for sensing deceleration of the towed vehicle, a means for generating a braking signal and a means for energizing the brakes of the towed vehicle. The method comprises the steps of sensing deceleration of the towed vehicle, determining a rate of deceleration of the towed vehicle, sensing a braking signal from a towing vehicle towing the towed vehicle, generating a braking signal within the braking control device wherein the braking signal is proportional to the rate of deceleration, energizing the brakes of the towed vehicle to initial engagement from the energy source upon sensing the braking signal from the towing vehicle and applying energy from energy source to the brakes of the towed vehicle proportional to the braking signal.
Another significant object of this invention is to provide a method of controlling the swaying of a towed vehicle using a braking control device onboard the towed vehicle. The method comprises a means for generating a swaying signal, a means for generating a braking signal and a means for energizing the brakes of the towed vehicle. The steps of the method include sensing at least two successive lateral movements of the towed vehicle within a given time, generating a swaying signal upon sensing the lateral movements, determining a rate of lateral movement of the towed vehicle, generating a braking signal within the braking control device wherein the braking signal is proportional to the rate of lateral movement and energizing the brakes of the towed vehicle proportional to the signal.
The primary purpose of the automated electronic brake control system of this invention mounted on the towed vehicle is to remove towed vehicle braking control devices from of the towing vehicle and transfer all towed vehicle braking functions to the towed vehicle by energizing the braking system of the towed vehicle from the braking system of the towing vehicle. The alternate purpose of the automated electronic brake control system of this invention mounted in the towing vehicle is to eliminate the manual operations required by the driver by providing a brake controller having capabilities of sensing a change of velocity in at least one direction and an automated system to apply the brakes dependent upon the severity the change of velocity.